Epoxy system preferences?

I do umpteen mixes in a week, and it's very very rare to get a soft cure  -  weighing - kitchen scales are good for mixes  30g  - 2 kg.  Pumps get gunked up, and don't measure accurately , so i use the big pumps for R and H just to get it out of the containers, but weigh everything.
e g for 320 - weigh resin , subtract 8g cup weight,  times 4, divide by three, add 8g = weight target with hardener.
I always have several kg of either resin or hardener left when it's time to buy more, so it's good to keep with the same system!
I think west 105, SP106, sicomin 5500 are very similar.
SP 320 is a bit thinner and flows better, maybe better properties. Fast cure even with slow H.
Sicomin SR8500 is thicker but is good when vaccing, fast H is relatively slow, and has good performance when cured at ~ 60°C

Yes its a real sod that you have to put all that stuff in the msds - it makes it easy for others to pick apart your systems without them even having to do any real chemistry,( like sticking it through the gc or ftir,) but then I have got quite a bit over the years from the msds 's of others, even though sometimes you suspect that they have the odd porkies in them!